The present invention is related to a method for the operation of a wind energy plant having a wind velocity measurement device, and to such a wind energy plant.
In the operation of wind energy plants, the wind velocity is a measured variable with a central influence on the capacity, the possible modes of operation and regulation and of the occurring loads of the wind energy plant. A reliable and accurate measurement of the wind velocity is of commensurate importance. Various types of wind velocity measurement devices are used, which are also designated as anemometers. They are in most cases disposed on the nacelle of the wind energy plant. A problem which can in principle be encountered by all wind velocity measurement devices is the monitoring of the measurement operation, i.e. to recognise a malfunction of the wind velocity measurement device. Erroneous measurement results may be caused by influences of the atmospheric conditions for instance, e.g. through icing of parts of the measurement device or other impurities. The requirements which the wind velocity measurement device must fulfil for a certification are deposited in the “Richtlinie für die Zertifizierung von Windenergieanlagen” of the Germanischer Lloyd, Ed. 2003 with supplement 2004 in chapter 2, paragraph 2.3.2.4.2, the entire contents of which is incorporated herein by reference.
Starting from these problems, the document DE 101 57 759 C1, the entire contents of which is incorporated herein by reference, proposes to correlate the measured wind velocity with additional operation parameters of the wind energy plant in a wind energy plant. Concretely, it is checked whether the power generated by the wind energy plant or a blade pitch angle resulting from the regulation of the wind energy plant is in a plausible interrelationship with the measured wind velocity. When this is not the case, an error of the anemometer is deduced.
Starting from this, it is the objective of the present invention to provide a method for the operation of a wind energy plant having a wind velocity measurement device, and such a wind energy plant which permit(s) an improved plausibility check of the measured wind velocity.